As semiconductor fabrication technologies are continually progressing, more and more challenges from defects on a wafer caused by accumulated charges have become important issue. For example, during an exposure/development process using an immersion lithography system, flowing water such as deionized (DI) water may introduce electrostatic charges. The accumulated electrostatic charges cause particle contamination such as particles adhering to surfaces of the immersion lithography system. The adhered particles may further migrate to a surface of the wafer and cause defects on the wafer and yield degradations.